Drier



Patented May 1937 UNITED STATES. PATENT OFFICE Arthur Minich, Newark, N. J., assignor to Nuodex Products 00., Inc., a corporation of New York N6 Drawing. Application April so, 1936.

- Serial No. 77,141

11 Claims. (Cl. 134-57) This invention is a drier and more particularly one adapted to be used in connection with the.

drying of paints, varnishes and enamels and especially of the character which embodies one or more drying metals, such as cobalt, manganese,

iron, and the like, inthe form of naphthenates, linoleates and the like. 1

My experience and research have convinced me that the ideal drier should possess the following 1 prerequisites:

It should remain in perfect solution for an indefinite period of storage.

.The metal contained in the driers should be of the highest degreeof availability of use.

15 The drier should have a minimum eifect upon the viscosity, flow, color and stability of the clear or pigmented vehicle in which it is incorporated. The drier should exhibit no adverse action upon the durability of thecoating in which it is incorporated.- -Th'e drier should not detrimentally affect the color retention properties of the vehicle in which it is used. The driershouldbe non-reactive with the pig- -ment portion of paints, varnishes and enamels.

The drier should retain its clarity and homogeneity even when exposed toair.

It should be in such concentrated form as to render it economical from the manufacturers and shippers standpoint. For example, it is found practical in cobalt ormanganese drier to utilize metal concentrations in the neighborhood of from 4% to 6%. r

A cobalt drier should be as blue as possible in '5 order'to effect some bleaching action upon the vehicle in which it is used.

. A manganese drier should be as pale as possible-so as to cause minimum discoloration in paints, varnishes andenamels inwhich it is ino corporated. f-

One of the most important of the foregoing prerequisites of the ideal'drier is that of stability. for, unless the drier is stable, it is open to serious disadvantages. For example, it may precipig recognized that a drier to be commercially practical must, when incorporating most of the drying metals, embody also an appropriate stabilizer and this has been recognized for years and there has grown up in the trade the accepted usage of acids for this purpose, it having been found that excess free acid when incorporated in the drier has a stabilizing function. It may be noted in this connection that common practice has dictated, for this purpose, amounts of acid varying from 2% to as high as based on the total.

weight of the solution. While a relatively large number of acids have been used for this purpose, the more commonly employed are naphthenic i acids, linseed oil fatty acids, benzoic acid, rosin,

etc. Experience has shown; however, that the inclusion of any of these acids as a stabilizing agent in driers introduces a number of serious disadvantages and these disadvantages are fairly well understood in the paint, varnish and enamel business. Those which are outstanding may be briefly enumerated as follows:

- The presence of free acid does not'asa matter of fact always guarantee permanent stability of the drier solutions. This is particularly true of rosin which, even in higher percentages, will not -perm-anently prevent gellation of a cobalt drier.

The presence of free acids, such as rosin, in

a drier, and thus ultimately in paint, varnish and The addition of sufficient free acid to be em.

tive as a stabilizer in a cobalt drier tends to r change the color of the latter fromblue to red I which is undesirable from a technical as well as a sales standpoint.

The presence of free acids, such as benzoic acid,- tends to make the drying performance of the metal uncertain.

Free acid such-as benzoic acidsa'r'e oiften' highly reactive with some of the pigments contained in paint and enamel and such an interaction tends to set up a decided increase in the body of the paint or enamel and ten'cls to impair the tone of some pigments, such as delicate maroon colors.

Under some conditions a drier-containing an efficiently with with acid as it would without.

Driers containing free acids exert at times very appreciable amount of free acid will not dry as v pronounced effects upon the physical characteristics of paints, varnishes and enamels causing increase in the viscosity of the paint and impairing the flowing qualities thereof.

The presence of some free acids, such'as linseed oil fatty acids, in driers and in the paint vehicle aggravate any tendency of the coating material to after-yellow which is especially no ticeable and objectionable in the case of white coatings.

As hereinbefore stated, many of thedisadvan tages to which'referencehas'been made have been recognized in the industry and much research has been madein an attempt to solve these problems. For example, it has been suggested touse butyl alcohol as a stabilizing agent in place of an acid stabilizer and such butyl alcohol has been employed to some extent. How-' ever, while it solves certain of the problems inherent in the use of acid, it introduces certain other problems which are even more serious in some respects.

Y highly volatile and the drier must be used almost immediately to obtain any'satisfaetory results.

If left uncovered it evaporates very rapidly and the stabilizing action is correspondingly de-' creased. It may also be noted that butyl alcohol and other volatile-stabilizers have a decided effect upon the viscosity of the paint, varnishor enamel vehicles and this too isundesirable. Experience has definitely shown that it is a practical impossibility to obtain uniform stabilizers with butyl alcohol for obvious reasons.

With the foregoing considerations in mind, it will be clear that a very definite need existed in the industry for a concentrated drier which will embody the ideal conditions to which I have referred and without the detrimental, features ad-' verted to. The object of the present invention was to produce such a drier.

I have found that metal driers of the character described may be very appreciably improved and in some casesmade practically'ideal through the employment of a stabilizing agent which is non-volatile, neutral, substantially water-insoluble and non-reactive-with the vehicle or pigments in which the drier is to be used and which has no noticeable effect upon the viscosity of the paint to which they may. be added. 'For example, I have obtained very satisfactory results with stabilizers having the properties of triethyl citrate, tributyl citrate, cyclo-hexyl-paratoluenesulfanamid particularly when employedin connection with naphthenate metal driers. These specified stabilizers materially increase the solubflity of the cobalt naphthenate in the mineral spirits and materially promote solubility in the combination and produce that permanent solubility so essential to an ideal drier. They are non-volatile and neutral and thus will notvolatilize off from the finished dried during storage,

and that attendant reaction which is so detri-" mental in acid stabilizers is entirely absent-in the stabilizers to which I have referred.

l The amount of stabilizer'needed is so small as not to affect the physical properties of. the paints, varnishes or enamels and a drier carrying from 4% to 6% cobalt, for example,-has been found stable and eflicient over long periods of time.

Other features and advantages of-the invention will hereinafter appear in connection with the following illustrative examples showing how For example, butyl alcohol is drlers embodying this invention have been practically produced.

' Example No. 1 Y To 440 pounds, of a suitable naphthenic acid there was added 9 pounds of cyclo-hexyl-paratoluene-sulfanamid. This was done with accom-. panying agitation. To this was added, with accompanying agitation, a solution carrying 88 pounds of flake-"caustic soda dissolved inv 400 pounds of water. To the resulting alkali-soap solution was added464 pounds of mineral spirits under thorough agitation. While the agitation was continued, there was finally introduced a solution of 295 pounds cobalt sulfate crystals in 400 pounds of water. The mixture was thereupon allowed to stratify and it was found that such- I stratification occurred promptly and was sharply defined. The supernatant liquid carrying a drier was decanted oil? and yielded 1,000 pounds of 6% cobalt naphthenate solutioncontaining approximately 1% of stabilizer. The above procedure may be carried out at room temperature, but can be speeded up at slightly elevated temperatures.

In lieu of the stratification and subsequent decantation referred to, it has beenfound thor oughly practical to mechanically separate in any appropriate way as by centrifuging.

Example No. 2

A similar procedure may be carried outusing approximately 27 pounds of the triethyl citrate in place of the 9 pounds of cyclo-hexyl-paratoluene- 'sulfanamid. I

- Example No.3 y A similar procedure may be carried out using approximately '27 poundsof the tributyl citrate in" place of the 9 pounds of cyclo-hexyl-para toluehe-sulfanamid- Example No. 4

A 6% manganese naphthenate solution containing triethyl citrate as stabilizer was prepared by adding to 450 pounds of naphthenic acid 28 pounds of triethyl citrate with good agitation.

Then a solution of 90% pounds of caustic soda in 400 pounds of water was introduced under continuedagitation. To the thus obtained alkalisoap-solution was added 487 pounds of mineral spirits and finallyQwhile agitation was continued,

a solution of 217 pounds manganese sulfate in 400 pounds of water was introduced. The resulting solution was found to stratify rapidly and completely and .was mechanically separated and it was found that theyield was approximately l,000 pounds of 6% manganese naphthenate drier containing 2.8% of the stabilizer. The use of moderate heats will speed upthe operation. It is also possible to operate with more-than one stabilizen'as will be apparent from the following example.

I Example No. 5 y

' enumerated in the examples given areliqu id Example No. a s

A 6% iron naphthenate solution. containing tributyl citrate'as stabilizer was prepared by adding to 488 pounds of a suitable naphthenic acid 30 pounds of tributyl citrate. This was done under thorough agitation. To this was added under agitation 97 pounds of flake caustic soda dissolved in 400 pounds of water. To the resultant alkali ify and it was found that such stratification occurred promptly and was'sharply defined. The supernatant liquid was found to yield 1,000 pounds of a 6% iron naphthenate solution containing approximately 3% of stabilizer.

I Example No. 7 I A 6% solution of copper naphthenate containing triethyl citrate as stabilizer was prepared by adding 30 poundsof triethyl citrate to 421 pounds forth practical methods of producing metal naph- 'in 400 pounds of water.

of a suitable naphthenic acid .with good agitation. Then a solution of 84 pounds of flake caustic soda in 400 pounds of water was added with thorough stirring. To the thus obtained alkali soap solution was 'added 481 pounds of mineral spirits and finally, while agitation was continued, a solution of 245 pounds of copper sulphate I The resultant solution was found to stratify rapidly and was mechanically separated and it: was found that theyield was approximately 1,000 pounds of 6% copper naphthenate solution containing 3% of stabilizer.

In all of the foregoing examples, I have set thenateswith stabilizers of the character under consideration through theprocess of. double decomposition. This process gives highly satisfactory results, but is not the only procedure, which may be followed. 0n the contrary, it is entirely feasible to-use any well known procedureknown to the art for the making of naphthenate driers of the kind herein under consideration, but the stabilizer or stabilizers to be employed should be incorporated into the drier by incorporation into the acid or into the acid mineral spirits solution before proceeding with the necessary chemical reactions which are involved in the production of metallic driers. I 7

Furthermore the foregoing examples deal with the making of metal naphthenate driers, but the invention may be carried out in the production of metallic driers of other acids of which the following may be referred to by way of example.

Example No. 8.

' 198 pounds of cobalt sulphate dissolved in 300 poundsof water. 'Iheresultingreaction mixture was allowed to separate and it was found that.

such stratification occurred promptly and was sharply defined. The supernatant liquid carrying a drier was decanted off and yielded approxi mately 1,000 pounds of a 4% cobalt linoleate solution containing 2% of stabilizer. 2

While the driers which have thus far been driers, carrying volatile. solvents, these solvents may be driven off in any appropriate way to yield driers in solid form, or, if desired, paste driers may be produced by leaving some of'the solvent in the drier or by adding any appropriate vehicle as will be well understood.

Driers made in the manner hereinbefore described are superior to driers heretofore used in.

the art. They are efficient, economical and uniform in their operation. They are permanent in character. They act expressly and solely as catalytic drying agents upon paint, varnish and enamelvehicles in which they are incorporated and exert no detrimental influence thereon.

Reference is made to the fact that the methyl citrate and cyclo-hexyl-paratoluene sulfanamid stabilizers of this-invention are practically insoluble in petroleum hydrocarbons and more particularly mineral spirits which are, commonly used as a solvent or diluent for driers and for paints,

" varnishes and enamels in which they are incorof triethyl citrate, tributyl citrate and cyclohexyl-paratoluene-sulfanarnid.

2. A drier comprising cobalt naphthenate and an organic alcohol derivative stabilizer selected from the group which consists of triethyl citrate, tributyl citrate and cyclo-hexyl-parato1uene-sulfanamid.

' 3. A drier comprising a water-insoluble manganese soap and an organic alcohol derivative stabilizer selected from the group which consists of triethyl citrate, tributyl citrate and cyclohexyl-paratoluene-sulfanamid. I

4; A drier comprising a water-insoluble iron soap and an organic alcohol derivative stabilizer selected from the group which consists of triethyl citrate, tributyl citrate and cyclo-hexyl-paratoluene-sulfanamid.

5. A drier comprising a water-insoluble soap of a drying metal dissolved in an organic thinner which solution-contains an organic alcohol derivative stabilizer selected from the group which consists of triethyl citrate, tributyl citrate and cyclo-hexyl paratoluene-sulfanamid.

6. A drier comprising a neutral, water-insoluble soap of a drying metal dissolved in an organic thinner which solution contains an organic alcohol derivative stabilizer selected from the group which consists of triethyl citrate, tributyl citrate and cyclo-hexyl-paratdluene-sulfanamid.

7. A drie'r comprising a metal naphthenate dissolved in an organic thinner and which solution contains an organic alcohol derivative stabilizer selected from the group which "consists of triethyl citrate, tributyl "citrate and cyclo-hexylparatoluene-sulfanamid.

8. A drier comprising cobalt naphthenate dissolved in an organicthinner and which solution contains an organic alcohol derivative stabilizer selected from the group which consists oi triethyl citrate, tributyl citrate and cyclo-hexylparato'luene-s'ulfanamid.

'9. A drier comprising manganese naphthenate dissolved in an organic thinner and which soluethyl citrate, tributyl citrate and cyclo-hexyiparatoluene-sulfanamid.

11. A drier comprising a water-insoluble cobalt soap and an organic alcohol derivative stabilizer selected from the group which consists of triethyl citrate, tributyl citrate, and cycio-hexylparatoluene-suli'anamid.

' ARTHUR MINICH. 

